Fabrication of three-dimensional porous La-doped SrTiO₃ microspheres with enhanced visible light catalytic activity for Cr(VI) reduction

Abstract

In recent years, much effort has been focused on the development of the photocatalysts with high performance under visible light irradiation. In this paper, three-dimensional porous La-doped SrTiO₃ (LST) microspheres were prepared by a modified sol–gel method, in which the agarose gel/SrCO₃ microsphere and La₂O₃ were employed as the template and the La resource, respectively. The as-prepared LST microspheres exhibit a porous structure with a diameter of about 10 µm and a surface pore size of about 100 nm. The La element was doped into the crystal lattice of SrTiO₃ by the substitution of La³⁺ for Sr²⁺. Therefore, the absorption edge of LST samples shifts toward the visible light region, and their photocatalytic activity for the Cr(VI) reduction is enhanced under visible light. Among all LST samples, LST-0.5 (the La³⁺ doping content is 0.5 wt-%) exhibited the highest visible-light photocatalytic activity, which can reduce 84% Cr(VI) within 100 min. This LST materials may become a promising photocatalyst for the facile treatment of wastewater containing poisonous heavy metal ions.

Graphical abstract

Keywords

SrTiO₃ / La³⁺ doping / porous microsphere / visible-light photocatalysis / Cr(VI) reduction

References

[1] Chen X B, Liu L, Yu P Y, Mao S S. Increasing solar absorption for photocatalysis with black hydrogenated titanium dioxide nanocrystals. Science, 2011, 331(6018): 746–750

[2] Nakata K, Fujishima A. TiO₂ photocatalysis: Design and applications. Journal of Photochemistry and Photobiology C, Photochemistry Reviews, 2012, 13(3): 169–189

[3] Tong H, Ouyang S X, Bi Y P, Umezawa N, Oshikiri M, Ye J H. Nano-photocatalytic materials: Possibilities and challenges. Advanced Materials, 2012, 43(10): 229–251

[4] Liu S Q, Yang M Q, Tang Z R, Xu Y J. A nanotree-like CdS/ZnO nanocomposite with spatially branched hierarchical structure for photocatalytic fine-chemical synthesis. Nanoscale, 2014, 6(13): 7193–7198

[5] Lan Y C, Lu Y L, Ren Z F. Mini review on photocatalysis of titanium dioxide nanoparticles and their solar applications. Nano Energy, 2013, 2(5): 1031–1045

[6] Li J T, Cushing S K, Bright J, Meng F K, Senty T R, Zheng P, Bristow A D, Wu N Q. Ag@Cu₂O core-shell nanoparticles as visible-light plasmonic photocatalysts. ACS Catalysis, 2013, 3(1): 47–51

[7] Xu H, Ouyang S X, Liu L Q, Reunchan P, Umezawa N, Ye J H. Recent advances in TiO₂-based photocatalysis. Journal of Materials Chemistry. A, Materials for Energy and Sustainability, 2014, 2(32): 12642–12661

[8] Hamad S, Hernandez N C, Aziz A, Ruiz-Salvador A R, Caleroa S, Grau-Crespo R. Electronic structure of porphyrin-based metal-organic frameworks and their suitability for solar fuel production photocatalysis. Journal of Materials Chemistry. A, Materials for Energy and Sustainability, 2015, 3(46): 23458–23465

[9] Shi J W, Guo L J. ABO₃-based photocatalysts for water splitting. Progress in Natural Science: Materials International, 2012, 22(6): 592–615

[10] Kuang Q, Yang S H. Template synthesis of single-crystal-like porous SrTiO₃ nanocube assemblies and their enhanced photocatalytic hydrogen evolution. ACS Applied Materials & Interfaces, 2013, 5(9): 3683–3690

[11] Wang B, Shen S H, Guo L J. SrTiO₃ single crystals enclosed with high-indexed (023) facets and (001) facets for photocatalytic hydrogen and oxygen evolution. Applied Catalysis B: Environmental, 2015, 166-167: 320–326

[12] Ouyang S, Li P, Xu H, Tong H, Liu L Q, Ye J H. Bifunctional-nanotemplate assisted synthesis of nanoporous SrTiO₃ photocatalysts toward efficient degradation of organic pollutant. ACS Applied Materials & Interfaces, 2014, 6(24): 22726–22732

[13] Wang J S, Yin S, Zhang Q W, Saito F, Sato T. Mechanochemical synthesis of SrTiO_3−xF_x with high visible light photocatalytic activities for nitrogen monoxide destruction. Journal of Materials Chemistry, 2003, 13(9): 2348–2352

[14] Zhang Y B, Zhong L, Duan D P. Single-step hydrothermal synthesis of strontium titanate nanoparticles from crystalline anatase titanium dioxide. Ceramics International, 2015, 41(10): 13516–13524

[15] Irie H, Maruyama Y, Hashimoto K. Ag⁺- and Pb²⁺-doped SrTiO₃ photocatalysts: A correlation between band structure and photocatalytic activity. Journal of Materials Chemistry. C, Materials for Optical and Electronic Devices, 2007, 111(4): 1847–1852

[16] Zou J P, Zhang L Z, Luo S L, Leng L H, Luo X B, Zhang M J, Luo Y, Guo G C. Preparation and photocatalytic activities of two new Zn-doped SrTiO₃ and BaTiO₃ photocatalysts for hydrogen production from water without cocatalysts loading. International Journal of Hydrogen Energy, 2012, 37(22): 17068–17077

[17] Kou J H, Gao J, Li Z S, Yu H, Zhou Y, Zou Z G. Construction of visible-light-responsive SrTiO₃ with enhanced CO₂ adsorption ability: Highly efficient photocatalysts for artificial photosynthesis. Catalysis Letters, 2015, 145(2): 640–646

[18] Sukpanish P, Lertpanyapornchai B, Yokoi T, Ngamcharussrivichai C. Lanthanum-doped mesostructured strontium titanates synthesized via sol-gel combustion route using citric acid as complexing agent. Materials Chemistry and Physics, 2016, 181: 422–431

[19] Marshall M S J, Newell D T, Payne D J, Egdell R G, Castell M R. Atomic and electronic surface structures of dopants in oxides: STM and XPS of Nb- and La-doped SrTiO₃ (001). Physical Review B: Condensed Matter and Materials Physics, 2011, 83(3): 035410

[20] Wang J S, Yin S, Komats M, Zhang Q W, Saito F, Sato T. Preparation and characterization of nitrogen doped SrTiO₃ photocatalyst. Journal of Photochemistry and Photobiology A Chemistry, 2004, 165(1): 149–156

[21] Wang J S, Yin S, Komatsu M, Zhang Q W, Saito F, Sato T. Photo-oxidation properties of nitrogen doped SrTiO₃ made by mechanical activation. Applied Catalysis B: Environmental, 2004, 52(1): 11–21

[22] Ohno T, Tsubota T, Nakamura Y, Sayama K. Preparation of S, C cation-codoped SrTiO₃ and its photocatalytic activity under visible light. Applied Catalysis A, General, 2005, 288(1-2): 74–79

[23] Puangpetch T, Sommakettarin P, Chavadej S, Sreethawong T. Hydrogen production from water splitting over Eosin Y-sensitized mesoporous-assembled perovskite titanate nanocrystal photocatalysts under visible light irradiation. International Journal of Hydrogen Energy, 2010, 35(22): 12428–12442

[24] Townsend T K, Browning N D, Osterloh F E. Nanoscale strontium titanate photocatalysts for overall water splitting. ACS Nano, 2012, 6(8): 7420–7426

[25] Xue C, An H, Yan X Q, Li J L, Yang B L, Wei J, Yang G D. Spatial charge separation and transfer in ultrathin CdIn₂S₄/rGO nanosheet arrays decorated by ZnS quantum dots for efficient visible-light-driven hydrogen evolution. Nano Energy, 2017, 39: 513–523

[26] Lin B, Li H, An H, Hao W B, Wei J, Dai Y Z, Ma C S, Yang G D. Preparation of 2D/2D g-C₃N₄ nanosheet@ZnIn₂S₄ nanoleaf heterojunctions with well-designed high-speed charge transfer nanochannels towards high efficiency photocatalytic hydrogen evolution. Applied Catalysis B: Environmental, 2018, 220: 542–552

[27] Xue C, Yan X Q, An H, Li H, Wei J, Yang G D. Bonding CdS-Sn₂S₃ eutectic clusters on graphene nanosheets with unusually photoreaction-driven structural reconfiguration effect for excellent H₂ evolution and Cr(VI) reduction. Applied Catalysis B: Environmental, 2018, 222: 157–166

[28] Kanhere P, Chen Z. A review on visible light active perovskite-based photocatalysts. Molecules (Basel, Switzerland), 2014, 19(12): 19995–20022

[29] Schultz A M, Brown T D, Ohodnicki P R. Optical and chemi-resistive sensing in extreme environments: La-doped SrTiO₃ films for hydrogen sensing at high temperatures. Journal of Materials Chemistry. C, Materials for Optical and Electronic Devices, 2015, 119(11): 6211–6220

[30] Miyauchi M, Takashio M, Tobimatsu H. Photocatalytic activity of SrTiO₃ codoped with nitrogen and lanthanum under visible light illumination. Langmuir, 2004, 20(1): 232–236

[31] Lin B, Yang G D, Yang B L, Zhao Y X. Construction of novel three dimensionally ordered macroporous carbon nitride for highly efficient photocatalytic activity. Applied Catalysis B: Environmental, 2016, 198(3): 276–285

[32] Lin B, An H, Yan X Q, Zhang T X, Wei J J, Yang G D. Fish-scale structured g-C₃N₄ nanosheet with unusual spatial electron transfer property for high-efficiency photocatalytic hydrogen evolution. Applied Catalysis B: Environmental, 2017, 210: 173–183

[33] Pan J H, Cai Z C, Yu Y, Zhao X S. Controllable synthesis of mesoporous F-TiO₂ spheres for effective photocatalysis. Journal of Materials Chemistry, 2011, 21(30): 11430–11438

[34] Pan J H, Zhang X, Du Alan J, Sun D D, Leckie J O. Self-etching reconstruction of hierarchically mesoporous F-TiO₂ hollow microspherical photocatalyst for concurrent membrane water purifications. Journal of the American Chemical Society, 2008, 130(34): 11256–11257

[35] Huang Y, Gao Y X, Zhang Q, Cao J J, Huang R J, Ho W K, Lee S C. Hierarchical porous ZnWO₄ microspheres synthesized by ultrasonic spray pyrolysis: Characterization, mechanistic and photocatalytic NO_x removal studies. Applied Catalysis A, General, 2016, 515: 170–178

[36] Yang D, Sun Y Y, Tong Z W, Nan Y H, Jiang Z Y. Fabrication of bimodal-pore SrTiO₃ microspheres with excellent photocatalytic performance for Cr(VI) reduction under simulated sunlight. Journal of Hazardous Materials, 2016, 312: 45–54

[37] Shi L, Wang T, Zhang H B, Chang K, Meng X G, Liu H M, Ye J H. An amine-functionalized iron(III) metal-organic framework as efficient visible-light photocatalyst for Cr(VI) reduction. Advancement of Science, 2015, 2(3): 1500006

[38] Zheng Z K, Huang B B, Qin X Y, Zhang X Y, Dai Y, Jiang M H, Wang P, Whangbo M H. Highly efficient photocatalyst: TiO₂ microspheres produced from TiO₂ nanosheets with a high percentage of reactive (001) facets. Chemistry (Weinheim an der Bergstrasse, Germany), 2009, 15(46): 12576–12579

[39] Qin Y, Wang G Y, Wang Y J. Study on the photocatalytic property of La-doped CoO/SrTiO₃ for water decomposition to hydrogen. Catalysis Communications, 2007, 8(6): 926–930

[40] Chen X, Cheng J P, Shou Q L, Liu F, Zhang X B. Effect of calcination temperature on the porous structure of cobalt oxide micro-flowers. CrystEngComm, 2012, 14(4): 1271–1276

[41] Pan J H, Shen C, Ivanova I, Zhou N, Wang X Z, Tan W C, Xu Q H, Bahnemann D W, Wang Q. Self-template synthesis of porous perovskite titanate solid and hollow submicrospheres for photocatalytic oxygen evolution and mesoscopic solar cells. ACS Applied Materials & Interfaces, 2015, 7(27): 14859–14869

[42] Li H Q, Cui Y M, Wu X C, Hong W S, Hua L. Effect of La contents on the structure and photocatalytic activity of La-SrTiO₃ catalysts.Chinese Journal of Inorganic Chemistry, 2012, 28(12): 2597–2604

[43] Zhang J Y, Zhao Z Y, Wang X Y, Yu T, Guan J, Yu Z T, Li Z S, Zou Z G. Increasing the oxygen vacancy density on the TiO₂ surface by La-doping for dye-sensitized solar cells. Journal of Physical Chemistry C, 2010, 114(43): 18396–18400

[44] Yao S H, Jia X Y, Jiao L L, Zhu C, Shi Z L. La-doped TiO₂ hollow fibers and their photocatalytic activity under UV and visible light. Indian Journal of Chemistry, 2012, 51(8): 1049–1056

[45] Marina O A, Canfield N L, Stevenson J W. Thermal, electrical, and electrocatalytical properties of lanthanum-doped strontium titanate. Solid State Ionics, 2002, 149(1): 21–28

[46] Zhou X, Zhang X N, Feng X B, Zhou J, Zhou S Q. Preparation of a La/N co-doped TiO₂ film electrode with visible light response and its photoelectrocatalytic activity on a Ni substrate. Dyes and Pigments, 2016, 125(12): 375–383

[47] Zhang Y, Zhao Z Y, Chen J R, Cheng L, Chang J, Sheng W C, Hu C Y, Cao S S. C-doped hollow TiO₂ spheres: In situ synthesis, controlled shell thickness, and superior visible-light photocatalytic activity. Applied Catalysis B: Environmental, 2015, 165: 715–722

[48] Ng J W, Xu S P, Zhang X W, Yang H Y, Sun D D. Hybridized nanowires and cubes: A novel architecture of a heterojunctioned TiO₂/SrTiO₃ thin film for efficient water splitting. Advanced Functional Materials, 2010, 20(24): 4287–4294

[49] Wang C D, Qiu H, Inoue T, Yao Q W. Highly active SrTiO₃ for visible light photocatalysis: A first-principles prediction. Solid State Communications, 2014, 181(3): 5–8

[50] Wang A, Shen S, Zhao Y, Wu W. Preparation and characterizations of BiVO₄/reduced graphene oxide nanocomposites with higher visible light reduction activities. Journal of Colloid and Interface Science, 2015, 445: 330–336

[51] Chen X, Ta P F, Zhou B H, Dong H G, Pan J, Xiong X. A green and facile strategy for preparation of novel and stable Cr-doped SrTiO₃/g-C₃N₄ hybrid nanocomposites with enhanced visible light photocatalytic activity. Journal of Alloys and Compounds, 2015, 647(2): 456–462

[52] Qiu B C, Zhong C C, Xing M Y, Zhang J L. Facile preparation of C-modified TiO₂ supported on MCF for high visible-light-driven photocatalysis. RSC Advances, 2015, 5(23): 17802–17808

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